Pretty much, the DE0 which most of the retro fpga computers rely on, was cheap, but it is almost impossible to find at decent prices anymore, even the non-mainstream FPGA boards (WaveShare, etc) have jumped in price massively, even though they're really pretty useless for retro computing use unless you're willing to reinvent the entire universe to bake an apple pie.

Regarding MiSTer :

Whether or not the 2023 entry price of a few hundred US dollars plus shipping (that is, a $225 DE10Nano board + $65 RAM module, with basic analog outs and USB able to be added via ~$20 generic dongles) is a ripoff or not, for a system that uses FPGA tech to simulate/emulate a large range of old computers and consoles to a leading standard, including a long (ever-growing) and impressive feature list of options, and a very stable longterm front-end ...is quite subjective.

I think it's still exceedingly good value. But certainly not the only, or outright cheapest, option.

That's odd. Whatever you could get 5-7 years ago is still available (except better) for pretty much the same or lower prices and with a lot more examples to start from.

How is that world a ripoff?

If you're willing to do some grunt work, there's still cheap boards to be found on alibaba and the like.